Require members to sign in to Member Portal with Ethereum

[willyogo]

Currently the token gate on the member portal doesn't use sign in with ethereum. In theory, a user could use a wallet like frame that lets you inject any address and connect to the member portal without actually being a member.

As platform admins, we want to implement Sign in with Ethereum to ensure that only members can access

AC:

1. In order to access the members portal, users need to sign a message with an account holding an ATXDAO nft